Minute openings sometimes are present in the peripheral wall of automotive wheel rims after the manufacturing process is complete, which openings allow the escape of air while the rims are in service. The use of perfectly sealed rims is necessitated by "tubeless" tires, i.e., tires which do not employ inner tubes. Such openings commonly may be extremely minute and yet at normal inflation pressures (32 psig), allow sufficient air to escape to cause very gradual deflation of the tire, creating an increased need for tire servicing to maintain proper inflation pressures.
Auto wheel rims are configures in a large number of varying sizes and configurations, such that fixturing for leak testing must be extensive if each fixture is adapted to a given rim size.
It is important in the production environment that tests be conducted quickly and reliably, and yet very minute leaks must be detected in order to eliminate the problem of gradual tire deflation.
So called "trace" gas methods are known which are capable of quickly detecting minute leaks.
It is an object of the present invention to provide a method and apparatus for leak testing of auto tire wheel rims which is able to quickly detect very minute leaks through the rim peripheral wall.
It is yet another object of the present invention to provide such a method and apparatus which will readily accomodate wheel rims of varying sizes and configuration with the use of a single fixture.
It is an object to provide a trace gas leak detection method and apparatus which enables such rim leak testing. while providing reliable test results to be adapted to production testing of wheel rims.